The present invention relates to a visual wear indicator for an adjustable braking system. In known braking systems, an input to a lever rotates an eccentric rotatably mounted in an actuating block. A load plate bearing friction material is mounted to the actuating block. Upon rotation of the eccentric, the actuating block, load plate and friction material are moved towards a rotor, causing the friction material to contact the rotor. The friction material causes resistance to the motion of the rotor.
Normally the friction material is maintained slightly out of contact with the rotor when the braking system is in the non-activated or rest position. Gradually the friction material becomes worn, and is spaced further and further away from the rotor, reducing the braking power of the braking system. Adjustment assemblies adjust the distance of the friction material from the rotor.
One such adjustment assembly is disclosed in co-pending application Ser. Nos. 08/747,141 and 08/747,139, the assignee of which is the assignee of the present invention. In that system, an eccentric is rotatably mounted within an actuator block. Rotation of the eccentric reciprocates the actuation block, moving a pair of adjusting sleeves toward the rotor. A threaded connector is threaded within each adjusting sleeve and abuts an adjusting piston. Both adjusting pistons are bolted to a load plate which is secured to a backing plate and friction material. Upon rotation of the eccentric, the actuation block reciprocates, driving the actuation sleeves, threaded connectors, adjusting pistons, load plate and friction material forwardly against the rotor. In order to adjust the braking position of the load plate as the friction material becomes worn, the adjustment assembly adjusts the position of the and friction material relative to the actuation block. Rotation of the eccentric beyond a certain threshold causes rotation of an actuation gear section which causes rotation of the adjustment sleeves. Rotation of the adjustment sleeves causes axial movement of the non-rotatable threaded connectors (and consequently the adjusting pistons and load plate) toward the rotor relative to the actuation block. This system provides automatic adjustment of the braking position of the load plate and friction material; however, because the adjustment is automatic, it is difficult to determine when the friction material has become sufficiently worn that it must be replaced.